138 



REGENERATION 



The same method used to produce double tails in the lizard can 

 also be used to produce double legs. The femur is broken in the 

 vicinity of the hip-joint, and the soft parts are cut into over the break. 

 Then, or better somewhat later, the leg is amputated below the 



FlG. 43. After Tornier. A. Lacerta agilis. Produced by partly breaking off old tail. New tail 

 arises at place of breaking. Old tail also remains. B. Three-tailed form two tails being 

 united in a common covering. Old tail had been cut off (it regenerated the lower branch 

 from cut-end) and two proximal vertebrae that had been injured. C. Additional limb of 

 Triton cristatus produced by wounding femur. D. Double foot of Triton cristatus produced 

 by tying thread over regenerating stump. E. Foot of Triton cristatus. Dotted lines indicat- 

 ing how foot was cut off. F. Regeneration of same. G. Another way of cutting off foot. 

 H. Result of last operation. 



broken part. A new limb regenerates from the cut-end, and at the 

 same time another limb grows out from the broken femur (Fig. 43, C\ 

 The same result is reached if the femur has a slit cut into it in the 

 region of the hip-joint, so that it is much injured. Later the leg is 

 cut off below the place of injury. A double leg is the result. 



